At present, there is an unlimited number of containers designs used for storage and transportation of fruits and vegetables throughout the production chain, that is to say, from harvesting until the sale to the final consumer. Said diversity is associated to the active development that the packaging industry currently has, whose main target has been always the same, to search an optimal product having a cost and a weight as low as possible while it is robust and provides the necessary features for the intended use.
Thus, the existing relationship between the weight and the container structural strength has become a key factor, since reducing significantly the container weight many times may produce a loss of structural strength of the same which affects to a substantial extent the packaging conditions and the integrity of the products themselves. On the other hand, said loss of weight is associated to a reduced use of material, which leads to an important cost reduction, crucial issue in a competitive industry like the packaging industry where the use of plastic has been gradually taking away market share to the cardboard industry specially for its good resistive properties.
Therefore, the strength and weight parameters are critical in particular at the exports stage, where it is necessary that the container with products withstands the transport and storage conditions during extended periods of time and distances, also being relevant that it allows to maintain the products inside in excellent conditions protecting them from bumps and crushings often produced even because of poor conditions of the containers stacking which does not maintain their integrity when arranged in the pallet and also when the latter is subsequently fastened with moorings or “strapping”, as this operation is frequently called.
In this context, for the export of products in the fruits and vegetables industry, mainly when the transport distances are significantly, often it is preferred the use of plastic containers because they have a better structural strength and a better resistance to environmental conditions such as moisture, than the cardboard containers do. Said containers are organized in pallets and usually they are covered with a bag to preserve the products conditions for long periods of time when they are transported inside containers and refrigerated lorries.
Said containers are often called “One Way”, as the name implies, they have one way or direction, that is to say, they are sent from the place of origin to the place of destination without being used again for the same purpose, where they are regularly destroyed and subsequently recycled.
The state of the art describes some examples of One Way plastic containers, for example those disclosed by the Applicant in the Applications CL 879-2014 and CL 880-2014. Said Applications suggest a plastic container with collapsible walls whose objective is to significantly reduce weight but without sacrificing the structural strength.
In order to achieve this objective, the Application CL 879-2014 suggests a novel light connection system between the containers walls, consisting of a clip type closure device incorporating a hollow tubular column fixed to the faces. By means of this connection system it is possible to significantly reduce the amount of material in the containers corners without lowering the structural strength even increasing it, since it takes advantage of the firm structure of the hollow column incorporated to the closure system which provides a firm and easy connection between the container walls.
In turn, the Application CL 880-2014 suggests a bottom for a collapsible plastic container which is able to reduce the container weight by means of the T shaped ribs of variable height strategically distributed in the bottom. Said ribs allow to efficiently distribute forces towards the container frame and therefore to avoid material in zones which do not require great forces.
With the systems suggested by the above mentioned references, the Applicant could reduce the weight of the plastic containers known at that time in approximately 11%, obtaining a container of just 310 grs. Nevertheless, currently the technology advances, the increasing demand of goods in the food industry and the commitment to reduce the carbon footprint, force manufacturing industries to continue improving their products.
Thus, although the containers suggested by documents CL 879-2014 and CL 880-2014 show a significant improvement in the strength to weight ratio, in order to satisfy the above mentioned issues, progressing to a second level is critical where the progress not only means to reduce production costs but also to provide improvements to ensure a better quality of the products transported in One Way containers minimizing the losses associated to damages done during the transport and storage processes and thus complying with the quality standards required by the horticulture industry for the export products.
Therefore, the objective of the present invention is to improve the above mentioned plastic containers of the state of the art furnishing a One Way container which provides a better strength to weight ratio. In particular, the aim is to produce a container weighing below 300 grs with sufficient stiffness so as to ensure the integrity of the products inside it and a controlled deformation on forces originated during palletizing maintaining its structure all the time.